Year Number of 1990 300.29 1991 302.54 1992 305.15 1993 307.1 1994 309.3 1995 311.86 1996 306.39 1997 301.03 1998 295.39 1999 290.22 2000 285.65 2001 289.99 2002 295 2003 301.24 2004 307.82 2005 314.78 2006 319.87 2007 325.04 2008 331.58 2009 338.55 2010 346.1 2011 353.35 2012 361.11 2013 369.3 2014 377.61 2015 385.94 2016 394.44